The present invention relates to a fitting or mounting part for a connection with a tube. The fitting part has an end section extending in a longitudinal direction, which end section can be pressed together for establishing a connection. The end section has a ring-shaped elevation in which a sealing ring is arranged. Such a fitting or such a mounting part is usually used for establishing a pressed connection. A tube end is inserted into the end section with the end section constructed as a connection piece with the tube, which are then cold-formed by a pressing tool.
In order to be able to recognize that a pressing point of such a connection is not yet pressed together, it is suggested in German Patent Document DE 100 07 914 and corresponding U.S. patent application Ser. No. 09/959,012 to provide a bulge at an elevation of the connection piece of the fitting or of the mounting part, by which bulge an intentional leakage is provided until a definite pressing-together has taken place. Such a bulge for an intended leakage in the not pressed-together condition has been successful per se because it is easily recognizable during a mounting whether the pressing together had accidentally been forgotten. However, it has to be ensured that, irrespective of how the pressing tool is applied to the end section, a tight pressed connection is provided.
Therefore, the present invention provides for a fitting or a mounting part which, in the not pressed-together condition, offers an intended leakage and which subsequently can be sealed off in a reliable manner by a pressing together.
According to the present invention, the fitting or mounting part includes an end section extending in a longitudinal direction, which end section can be pressed together with a tube for establishing a connection. The fitting or mounting part has a ring-shaped elevation on the end section forming a space, a sealing ring in the elevation space and at least one flow channel provided in the elevation. The flow channel extends diagonally to a plane in a longitudinal direction of the end section and changes a depth of the space. This diagonal arrangement of the flow channel lengthens the flow channel along the elevation having the sealing ring so that an area of the flow channel to be pressed together is also lengthened. As a result of the longer pressed distance, the reliability of the sealing is increased during the pressing because the flow channel can be pressed and sealed off at different points along its length. The flow channel may have a relatively small cross-section in order to minimize a stressing of the channel""s material during the pressing and to avoid a formation of cracks.
According to an embodiment of the invention, the flow channel is arranged at an angle of at least 10xc2x0, preferably more than 20xc2x0, with respect to the longitudinal direction of the end section. In the case of a tube-shaped construction of the end section, the longitudinal direction of the end section is the flow direction, the flow channel then extending on the interior side of the end section and the angle being measurable as seen in a sectional top view. The flow channel may be constructed uniformly at an angle with respect to the longitudinal direction or have one or more curvatures, so that the angle would have to be considered as an average value. If the end section is constructed in a tube shape, the flow channel would extend in a plane perpendicular to the longitudinal direction, preferably around at least one-tenth of the circumference of the end section. This ensures that at least a portion of the flow channel is arranged in an area which is not provided in the gap between two cheek plates of a pressing tool.
The length of the flow channel is greater than and may be at least five times as large as the width of the flow channel.
According to another embodiment, the flow channel extends in a thread-type manner in the longitudinal direction from one side of the elevation to the other side of the elevation. As a result, the flow channel is lengthened to an extreme degree and has to be sealed off in the area of the sealing ring only at an arbitrary point by pressing in order to ensure that the thus established connection arrangement will be permanently tight.
The flow channel may be formed by an indentation in the area of the elevation. This indentation may be a plastic indentation and may be formed by a stamping as well as by a reduction of the wall thickness of the elevation.
In its cross-section, the flow channel preferably has an essentially semi-circularly or semi-ovally open construction toward the interior side of the end section. The height of the flow channel, thus the distance between the end section and the sealing ring, is relatively short in order to obtain a tightening even by means of a small deformation and in order to minimize the stressing of the material in the area of the flow channel during the pressing. In this case, the flow channel may have a rounded construction at the transition to the elevation or to the end section so that no sharp edges are formed which could damage the sealing ring.
The connection arrangement between the fitting part and the tube may be used in the field of sanitary installations or when laying other pipes or tubes.
These and other aspects of the present invention will become apparent from the following detailed description of the invention, when considered in conjunction with accompanying drawings.